/**
 * @license Angular v19.2.2
 * (c) 2010-2025 Google LLC. https://angular.io/
 * License: MIT
 */

export { s as setAlternateWeakRefImpl } from '../../weak_ref.d-ttyj86RV.js';

/**
 * A comparison function which can determine if two values are equal.
 */
type ValueEqualityFn<T> = (a: T, b: T) => boolean;
/**
 * The default equality function used for `signal` and `computed`, which uses referential equality.
 */
declare function defaultEquals<T>(a: T, b: T): boolean;

type Version = number & {
    __brand: 'Version';
};
/**
 * Symbol used to tell `Signal`s apart from other functions.
 *
 * This can be used to auto-unwrap signals in various cases, or to auto-wrap non-signal values.
 */
declare const SIGNAL: unique symbol;
declare function setActiveConsumer(consumer: ReactiveNode | null): ReactiveNode | null;
declare function getActiveConsumer(): ReactiveNode | null;
declare function isInNotificationPhase(): boolean;
interface Reactive {
    [SIGNAL]: ReactiveNode;
}
declare function isReactive(value: unknown): value is Reactive;
declare const REACTIVE_NODE: ReactiveNode;
/**
 * A producer and/or consumer which participates in the reactive graph.
 *
 * Producer `ReactiveNode`s which are accessed when a consumer `ReactiveNode` is the
 * `activeConsumer` are tracked as dependencies of that consumer.
 *
 * Certain consumers are also tracked as "live" consumers and create edges in the other direction,
 * from producer to consumer. These edges are used to propagate change notifications when a
 * producer's value is updated.
 *
 * A `ReactiveNode` may be both a producer and consumer.
 */
interface ReactiveNode {
    /**
     * Version of the value that this node produces.
     *
     * This is incremented whenever a new value is produced by this node which is not equal to the
     * previous value (by whatever definition of equality is in use).
     */
    version: Version;
    /**
     * Epoch at which this node is verified to be clean.
     *
     * This allows skipping of some polling operations in the case where no signals have been set
     * since this node was last read.
     */
    lastCleanEpoch: Version;
    /**
     * Whether this node (in its consumer capacity) is dirty.
     *
     * Only live consumers become dirty, when receiving a change notification from a dependency
     * producer.
     */
    dirty: boolean;
    /**
     * Producers which are dependencies of this consumer.
     *
     * Uses the same indices as the `producerLastReadVersion` and `producerIndexOfThis` arrays.
     */
    producerNode: ReactiveNode[] | undefined;
    /**
     * `Version` of the value last read by a given producer.
     *
     * Uses the same indices as the `producerNode` and `producerIndexOfThis` arrays.
     */
    producerLastReadVersion: Version[] | undefined;
    /**
     * Index of `this` (consumer) in each producer's `liveConsumers` array.
     *
     * This value is only meaningful if this node is live (`liveConsumers.length > 0`). Otherwise
     * these indices are stale.
     *
     * Uses the same indices as the `producerNode` and `producerLastReadVersion` arrays.
     */
    producerIndexOfThis: number[] | undefined;
    /**
     * Index into the producer arrays that the next dependency of this node as a consumer will use.
     *
     * This index is zeroed before this node as a consumer begins executing. When a producer is read,
     * it gets inserted into the producers arrays at this index. There may be an existing dependency
     * in this location which may or may not match the incoming producer, depending on whether the
     * same producers were read in the same order as the last computation.
     */
    nextProducerIndex: number;
    /**
     * Array of consumers of this producer that are "live" (they require push notifications).
     *
     * `liveConsumerNode.length` is effectively our reference count for this node.
     */
    liveConsumerNode: ReactiveNode[] | undefined;
    /**
     * Index of `this` (producer) in each consumer's `producerNode` array.
     *
     * Uses the same indices as the `liveConsumerNode` array.
     */
    liveConsumerIndexOfThis: number[] | undefined;
    /**
     * Whether writes to signals are allowed when this consumer is the `activeConsumer`.
     *
     * This is used to enforce guardrails such as preventing writes to writable signals in the
     * computation function of computed signals, which is supposed to be pure.
     */
    consumerAllowSignalWrites: boolean;
    readonly consumerIsAlwaysLive: boolean;
    /**
     * Tracks whether producers need to recompute their value independently of the reactive graph (for
     * example, if no initial value has been computed).
     */
    producerMustRecompute(node: unknown): boolean;
    producerRecomputeValue(node: unknown): void;
    consumerMarkedDirty(node: unknown): void;
    /**
     * Called when a signal is read within this consumer.
     */
    consumerOnSignalRead(node: unknown): void;
    /**
     * A debug name for the reactive node. Used in Angular DevTools to identify the node.
     */
    debugName?: string;
    /**
     * Kind of node. Example: 'signal', 'computed', 'input', 'effect'.
     *
     * ReactiveNode has this as 'unknown' by default, but derived node types should override this to
     * make available the kind of signal that particular instance of a ReactiveNode represents.
     *
     * Used in Angular DevTools to identify the kind of signal.
     */
    kind: string;
}
/**
 * Called by implementations when a producer's signal is read.
 */
declare function producerAccessed(node: ReactiveNode): void;
/**
 * Increment the global epoch counter.
 *
 * Called by source producers (that is, not computeds) whenever their values change.
 */
declare function producerIncrementEpoch(): void;
/**
 * Ensure this producer's `version` is up-to-date.
 */
declare function producerUpdateValueVersion(node: ReactiveNode): void;
/**
 * Propagate a dirty notification to live consumers of this producer.
 */
declare function producerNotifyConsumers(node: ReactiveNode): void;
/**
 * Whether this `ReactiveNode` in its producer capacity is currently allowed to initiate updates,
 * based on the current consumer context.
 */
declare function producerUpdatesAllowed(): boolean;
declare function consumerMarkDirty(node: ReactiveNode): void;
declare function producerMarkClean(node: ReactiveNode): void;
/**
 * Prepare this consumer to run a computation in its reactive context.
 *
 * Must be called by subclasses which represent reactive computations, before those computations
 * begin.
 */
declare function consumerBeforeComputation(node: ReactiveNode | null): ReactiveNode | null;
/**
 * Finalize this consumer's state after a reactive computation has run.
 *
 * Must be called by subclasses which represent reactive computations, after those computations
 * have finished.
 */
declare function consumerAfterComputation(node: ReactiveNode | null, prevConsumer: ReactiveNode | null): void;
/**
 * Determine whether this consumer has any dependencies which have changed since the last time
 * they were read.
 */
declare function consumerPollProducersForChange(node: ReactiveNode): boolean;
/**
 * Disconnect this consumer from the graph.
 */
declare function consumerDestroy(node: ReactiveNode): void;

/**
 * A computation, which derives a value from a declarative reactive expression.
 *
 * `Computed`s are both producers and consumers of reactivity.
 */
interface ComputedNode<T> extends ReactiveNode {
    /**
     * Current value of the computation, or one of the sentinel values above (`UNSET`, `COMPUTING`,
     * `ERROR`).
     */
    value: T;
    /**
     * If `value` is `ERRORED`, the error caught from the last computation attempt which will
     * be re-thrown.
     */
    error: unknown;
    /**
     * The computation function which will produce a new value.
     */
    computation: () => T;
    equal: ValueEqualityFn<T>;
}
type ComputedGetter<T> = (() => T) & {
    [SIGNAL]: ComputedNode<T>;
};
/**
 * Create a computed signal which derives a reactive value from an expression.
 */
declare function createComputed<T>(computation: () => T): ComputedGetter<T>;

type ComputationFn<S, D> = (source: S, previous?: {
    source: S;
    value: D;
}) => D;
interface LinkedSignalNode<S, D> extends ReactiveNode {
    /**
     * Value of the source signal that was used to derive the computed value.
     */
    sourceValue: S;
    /**
     * Current state value, or one of the sentinel values (`UNSET`, `COMPUTING`,
     * `ERROR`).
     */
    value: D;
    /**
     * If `value` is `ERRORED`, the error caught from the last computation attempt which will
     * be re-thrown.
     */
    error: unknown;
    /**
     * The source function represents reactive dependency based on which the linked state is reset.
     */
    source: () => S;
    /**
     * The computation function which will produce a new value based on the source and, optionally - previous values.
     */
    computation: ComputationFn<S, D>;
    equal: ValueEqualityFn<D>;
}
type LinkedSignalGetter<S, D> = (() => D) & {
    [SIGNAL]: LinkedSignalNode<S, D>;
};
declare function createLinkedSignal<S, D>(sourceFn: () => S, computationFn: ComputationFn<S, D>, equalityFn?: ValueEqualityFn<D>): LinkedSignalGetter<S, D>;
declare function linkedSignalSetFn<S, D>(node: LinkedSignalNode<S, D>, newValue: D): void;
declare function linkedSignalUpdateFn<S, D>(node: LinkedSignalNode<S, D>, updater: (value: D) => D): void;

interface SignalNode<T> extends ReactiveNode {
    value: T;
    equal: ValueEqualityFn<T>;
}
type SignalBaseGetter<T> = (() => T) & {
    readonly [SIGNAL]: unknown;
};
interface SignalGetter<T> extends SignalBaseGetter<T> {
    readonly [SIGNAL]: SignalNode<T>;
}
/**
 * Create a `Signal` that can be set or updated directly.
 */
declare function createSignal<T>(initialValue: T): SignalGetter<T>;
declare function setPostSignalSetFn(fn: (() => void) | null): (() => void) | null;
declare function signalSetFn<T>(node: SignalNode<T>, newValue: T): void;
declare function signalUpdateFn<T>(node: SignalNode<T>, updater: (value: T) => T): void;
declare function runPostSignalSetFn(): void;
declare const SIGNAL_NODE: SignalNode<unknown>;

declare function setThrowInvalidWriteToSignalError(fn: <T>(node: SignalNode<T>) => never): void;

/**
 * A cleanup function that can be optionally registered from the watch logic. If registered, the
 * cleanup logic runs before the next watch execution.
 */
type WatchCleanupFn = () => void;
/**
 * A callback passed to the watch function that makes it possible to register cleanup logic.
 */
type WatchCleanupRegisterFn = (cleanupFn: WatchCleanupFn) => void;
interface Watch {
    notify(): void;
    /**
     * Execute the reactive expression in the context of this `Watch` consumer.
     *
     * Should be called by the user scheduling algorithm when the provided
     * `schedule` hook is called by `Watch`.
     */
    run(): void;
    cleanup(): void;
    /**
     * Destroy the watcher:
     * - disconnect it from the reactive graph;
     * - mark it as destroyed so subsequent run and notify operations are noop.
     */
    destroy(): void;
    [SIGNAL]: WatchNode;
}
interface WatchNode extends ReactiveNode {
    hasRun: boolean;
    fn: ((onCleanup: WatchCleanupRegisterFn) => void) | null;
    schedule: ((watch: Watch) => void) | null;
    cleanupFn: WatchCleanupFn;
    ref: Watch;
}
declare function createWatch(fn: (onCleanup: WatchCleanupRegisterFn) => void, schedule: (watch: Watch) => void, allowSignalWrites: boolean): Watch;

/**
 * Execute an arbitrary function in a non-reactive (non-tracking) context. The executed function
 * can, optionally, return a value.
 */
declare function untracked<T>(nonReactiveReadsFn: () => T): T;

export { type ComputationFn, type ComputedNode, type LinkedSignalGetter, type LinkedSignalNode, REACTIVE_NODE, type Reactive, type ReactiveNode, SIGNAL, SIGNAL_NODE, type SignalGetter, type SignalNode, type ValueEqualityFn, type Watch, type WatchCleanupFn, type WatchCleanupRegisterFn, consumerAfterComputation, consumerBeforeComputation, consumerDestroy, consumerMarkDirty, consumerPollProducersForChange, createComputed, createLinkedSignal, createSignal, createWatch, defaultEquals, getActiveConsumer, isInNotificationPhase, isReactive, linkedSignalSetFn, linkedSignalUpdateFn, producerAccessed, producerIncrementEpoch, producerMarkClean, producerNotifyConsumers, producerUpdateValueVersion, producerUpdatesAllowed, runPostSignalSetFn, setActiveConsumer, setPostSignalSetFn, setThrowInvalidWriteToSignalError, signalSetFn, signalUpdateFn, untracked };